1. Field of the Invention
The present invention relates to specialty pads, and more particularly pertains to padding used by nonambulatory persons as bed pads to distribute the contact between parts of their body and a reclining surface, and further, to maximize aeration of body parts in contact with the pad. Proper weight distribution and adequate aeration can prevent the occurrence of decubitus ulcers and aid in the healing process once an ulcer has formed.
2. Description of the Prior Art
Decubitus ulcers or pressure sores can form on parts of the body where blood circulation is restricted due to the application of pressure thereon. For a patient in repose, such pressures are typically applied by the body weight to skin areas overlying bony prominences such as the sacrum, the shoulder blades, the spine, the elbows and the heels. The restriction of blood flow reduces the amount of oxygen and nutrients available to the affected tissue and causes waste to accumulate. Cells die, the tissue degenerates, and an open festering wound develops.
Those concerned with manufacturing and selling pads to be used by nonambulatory persons have been aware that properly distributed support and ample air circulation can reduce the occurrence of decubitus ulcers. Once a sore has developed, increased air circulation can aid in the healing process.
An open-cell foam pad that has been cut to form an alternating array of flat-topped projections and ventilated depressions has been found to be beneficial in preventing the formation of decubitus ulcers. U.S. Pat. No. 4,686,724, issued to Bedford on Aug. 16, 1987, describes in detail the advantages of such a pad. Alternative pad designs, in addition to methods of manufacture, are disclosed in U.S. Pat. No. 4,603,445 issued to Spann on Aug. 5, 1986.
U.S. Pat. No. 3,266,064, issued to Figman on Aug. 16, 1966, discloses a rather complex design in which cooled or heated air is forced to the surface of a mattress from a ventilated box spring. Bedford, in copending application Ser. No. 123,052 filed on Nov. 19, 1987, discloses a ventilated pad utilizing multilayer all-foam construction incorporating a booster fan in its center.
Most of the disclosed designs fail to simultaneously provide for adequate weight distribution as well as adequate fresh airflow to the supported portions of the anatomy by relying on passive diffusion to move air throughout the pad. Those designs that do provide an additional boost to the airflow are complex devices and expensive to manufacture. The disclosed designs all lack the ability to tailor the amount of ventilation to a particular patient's needs.